After the discovery of adult stem cells, these cells became the subject of intense experimental and clinical investigation for tissue regeneration. Bone marrow-derived adult stem cells consist of hematopoietic and mesenchymal stem cells. In 1997, Asahara’s group found vascular stem cells named endothelial progenitor cells (EPCs) within the hematopoietic stem cell population. After the identification of EPCs, investigators focused on their involvement in the treatment of ischemia and tissue regeneration. After injury or ulceration, bone marrow-derived EPCs are mobilized into peripheral blood and recruited to the foci of pathophysicological neovascularization and reendothelialization, thereby contributing to vascular regeneration and wound healing. Topical application of EPCs and their injection in tissue regeneration have shown success in preclinical studies and human clinical trials and are now under investigation by various facilities. However, in certain diseases, EPCs are reported to have impaired mobilization, proliferation, adhesion, differentiation and tubular formation. In this review, we focus on the biology of EPCs and the future possibilities of EPC therapy for therapeutic vasculogenesis.